Long Range Winter Speculation 2018/19

[Carvers Gap]

The NAO question in the mid-long range thread got me to thinking(always a dangerous proposition), does a -NAO actually produce more winter wx in the middle and western forum areas (middle and west TN/KY, and northern Alabama/ MS)?  OR is a -AO the better set-up w a +PNA.  NE TN is a bit different.  We can actually get by w a couple of different set-ups.  The -NAO has tendency to allow more coastals which can really hammer the mtns and eastern valley.  However, those coastals seem to have trouble reaching Nashville and Memphis.  Also, for you folks in Chattanooga...does a -NAO help for you all as well?  Folks from western KY/northern MS/northern AL feel free to jump in as well....

My favorite pattern here is a -NAO because Kingsport is in a rains shadow when it comes to upslope snow.  So, sometimes the patterns that produce upslope (+PNA or -EPO) don't work as well here.  We have to have help from the Atlantic.  Seems like the Plateau and westward requires a more favorable Pacific.  I am always interested in this debate and flip/flop often.  LOL.  @*Flash*, I am tagging you since we were discussing this in the other thread to some extent and wanted to continue the conversation(you need to take a water cooler break so that you talk weather more.).  @John1122 always has some interesting comments regarding Pacific/Atlantic setups for winter...

[nrgjeff]

Chattanooga benefits from -NAO most of the time. Even if it tries to run the Apps, the -NAO can save us and nudge it east/south. Yes it's billiard ball meteorology, lol! 

All of the above is best for Chatty, though it can mean late gin-up form MEM/BNA. All of the above can mitigate dry NW flow -NAO with a trough coming out of Texas.

[nrgjeff]

ECMWF monthly charts just came out. Euro keeps winter a little colder than normal, no big changes from last issue. Much more consistent than the CFS, but I guess that's not news. February still looks best for snow (verbatim). January (verbatim) risks drier NW flow and/or gin up over the Carolinas up the East Coast. However, those are monthly average heights/temps; so, anything can happen. December is less cold (no surprise) but storm track (verbatim) is not horrible. 

Clusters show the following. That December OK is actually a split between cold and disappointing Apps cutters 52/48%. January is 60% cold and 40% somewhat mild here; but the cold is cluster is stronger than the warm, netting cold odds at least after MLK Day. Feb is cold or colder. Both main clusters are friendly on the storm track if you like snow. March majority is similar with a smaller mild cluster, net cold signal.

[Carvers Gap]

@nrgjeff, what say you about the Euro Weeklies that rolled last night?  I thought they moved every so slightly off their spot during weeks 4-6.  Might just be a variation, but the western ridge looked stronger.  However, the expected downstream trough was in the country's mid-section.  I would think an eastern trough would be the result of the western pattern if it were to verify.  Also, thanks for the monthly chart update.... 

[nrgjeff]

Euro weeklies ease up the back weeks. CFS stays warmer, but it may be "stuck" in a phase. Euro seems reasonable with some ebb and flow going into fall.

Still next 10 days to two weeks look pretty warm. Then Euro has last third of September slightly warm, but not as warm as the CFS, and with more ebb and flow.

Most of the ridge anomalies are in the central US. In September wave length is still long enough that probably bleeds warmth this way. Cool Plains must be some sort of soil moisture feedback, but our Southeast 2m looks reasonable.

Week 6 Northwest ridge could have a cooler Southeast surface, but lingering SE warmth sometimes happens. Then again it's week 6. For now, TGIF!

[weathertree4u]

1 hour ago, Carvers Gap said:

I admittedly have not been following Florence that much...but the Euro run overnight(and the couple before that) were interesting.  Not sure if there is a Euro tropical bias at play(the 6z GFS recurved it while stalling it just east of the OBX), but that was a pretty Hugo-esque track.  The CMC also has a southern landfall.  For now, I lean towards the GFS as that looks realistic, but man....the Euro.  It has some support from the CMC and UKMET and its own ensemble.  The latest runs of the GFS and ICON recurve it.  If the Euro is anywhere close to being correct, there "could" be some impacts in NE TN and the mountains.  Still, at seven days anything could happen.  However, the NHC cone looks eerily like the 0z Euro before it ends.  @Windspeed, what do you think?  Is this making a landfall in the SE, and if so, do we feel the impacts in this area?  We really want no part of that monster.

I was thinking the same thing about Hugo, was in high school back then and can recall the huge impacts on the US - alarming is that there really are fewer and fewer escape options for Florence with each passing day. In addition, with each passing day, she inches closer and closer to that high octane water of the Gulf Stream. I honestly wonder if a projection of 145 is conservative? 

[jaxjagman]

I don't think this is more Hugo.Hugo came from a different longitude and latitude and even hit Puerto Rico.This seems to be a different beast and there has never been a hurricane to hit the  coast line without it re-curving away from the mainland since the 1850's?, with it's present location.

[stadiumwave]

I think you guys will like the European Seasonal update for DJF. Very similar to last month. 

On 9/6/2018 at 9:13 PM, Ginx snewx said:

Geezuz Euro seasonal would be awesome 

 

[Carvers Gap]

45 minutes ago, jaxjagman said:

I don't think this is more Hugo.Hugo came from a different longitude and latitude and even hit Puerto Rico.This seems to be a different beast and there has never been a hurricane to hit the  coast line without it re-curving away from the mainland since the 1850's?, with it's present location.

Was just commenting about how on the 0z Euro it had the SE coast to NE TN track and was still a strong storm far inland.  

[jaxjagman]

6 hours ago, Carvers Gap said:

Was just commenting about how on the 0z Euro it had the SE coast to NE TN track and was still a strong storm far inland.  

Cool,i was just saying this isn't near Hugo critique.The track of Hugo mentioned above isn't even close.The worse case of this storm is if the storm were to stall out of the Carolina's as the HP breaks down before it gets kicked out.

[Daniel Boone]

5 minutes ago, Carvers Gap said:

Florence on the 12z Euro pushes its precipitation and wind shield slightly closer to NE TN.  Stat tuned.  

If it's center comes into nw nc as depicted on Euro, it's rain shield will cover ne tn.

[Daniel Boone]

1 minute ago, Carvers Gap said:

Yep.  It is the most west of the models that I have seen.  However, the NHC is not far from its depiction w its cone.  If so, strong winds will be in the mountains and might be anyway as the winds funnel down the spine of the Apps on the east side.

Right with you on that Carvers. There may even be some fairly strong north downsloping winds in our area of which would cut back on rain amounts here but if euro track pans out, expect rains back to east ky at least for a time.

[kvskelton]

Thanks Carvers! I have been following Florence and was wondering if anyone was discussing the impact on the TN Valley area. Of course everything's still in flux and things may shift though the closer we get to landfall the more dialed in things will be. Really feeling sorry for folks up and down the coast within 100 miles either way of Wilmington, NC as it appears that area is the most likely for landfall at this time. Hurricanes are amazing to watch and track until you realize the tens of thousands of lives in their path.

I know one man who rode out Hugo just inland in his brick ranch house. He said it was the worst decision he ever made in his life. Luckily his wife had more sense than he did (isn't that often the case?) and evacuated to safer ground with their son. I'll never forget one quote he had:

"When the roof started bouncing up and down on the house, I knew then I'd made a really poor decision." 

[Holston_River_Rambler]

I'm glad for us in east TN and especially SW NC that the southern Apps aren't in the right quadrant of this sucker.  If it was sitting and spinning, even for 24 hours, over let's say Atlanta, I can't even imagine what upslope on the NC Blue Ridge would do.  Unfortunately VA Blue Ridge further north may find out if the Euro is right.  

What a high pressure ridge!  I can't remember (I am relatively young though) any hurricane on this trajectory stopping or dying in the Carolinas or VA.  Even the rare analogues that the twitterverse has been tossing out at least moved along.  The best analogy I can think of when watching the upper level flow, is looking at a river, where a shoal or log sticks into the current. Sometimes where the current rushes as it's forced by the object, there's an area inland from that point where the water sort of sits still or moves in unexpected ways, so that it if you run out of the current into the still water with a boat, you can sometimes just sit still and fish, with no anchor. Here I see the jet over Canada and northern US as the faster current and the high pressure ridge as the calm. 

I feel like it's kind of a wait and see mode at this point and we won't know if the "stall out" solution is right or wrong until she rolls inland.  All I can see as difference makers are the exact strength of the ridge and it's axis.  Looking at upper level potential vorticity on GFS ( https://imgur.com/a/YigeivZ ) there does seem to be a little bit of cyclonic vorticity that fujiwaras it inland a little bit, but that's all I can see. The Euro I have access to has a 300mb potential vorticity, but I'm not sure the two maps show exactly the same thing.  It does look quite a bit different. 

Euro image:

[Windspeed]

[mention=845]Windspeed[/mention], what do you think?  Is this making a landfall in the SE, and if so, do we feel the impacts in this area?  We really want no part of that monster.

Apologies, as I did not notice this until now. I think Florence does make landfall. It's current location and the WAR at 500mb is building into the Mid-Atlantic well enough to get the TC into the Carolinas. The big question for us is how ridging over the Ohio Valley to New England evolves versus surface highs / upper trough over Central and Upper Plains. If we're looking at a more amplified pattern / advancing trough, western edge of WAR should erode. Florence should run into a brick wall and the destructive precip shield should remain over Piedmont and coastal plain until it gets kicked out. However, if it is less amplified and Florence gets tucked under a negligible steering flow, stronger 500mb heights from Ohio to NE could leave a stall further NW or WNW over the Blue Ridge. That could potentially bring the destructive precip shield over W NC/VA highlands, perhaps even NE TN, SWVA. So closely watching how this plays out. I don't want to go all hyperbole at the risk yet because a lot can still change in 96-144 hrs range with respect to our neck of the woods.

[Bango]

12z Euro run puts the mountains out of the worst scenerio (extreme flooding), ...good news

[Bango]

5 minutes ago, Carvers Gap said:

IDK...I might have spoken to soon.  Looks like it backs over the Apps into E KY.  Precip and storm is weaker.  But if Florence does that(backs over the Apps at that pace), that is not good.

I see that.  This really really bears keeping an eye on for east tn, western nc/swva...some of those qpf amounts on this morning's euro run are/were scary, beyond 77' scary 

[nrgjeff]

Good news the 12Z Euro backed off QPF everywhere, but verbatim it's still very serious from the NC Piedmont into central Virginia. Given ensembles and other guidance I like the downward QPF around TRI and surrounding areas. Even the HWRF shifted right, though still the farthest west of the majors. Still 4-5 inches of rain is a lot of water to manage.

Indeed Florence could take a path rarely seen. From such a high latitude they usually get turned out to sea. Hugo did come from farther south. However in 2018 we have the Beast Ridge. Always a first time, or at least first in a long while. GFS is farther east/north because it weakens the ridge slightly relative to the Euro/ECMWF.

Brick wall stall remains the big question, so important for QPF. It is actually possible an influencing trough retrogrades in from the east in several days, after rounding the ridge from the north. That type of detail will definitely change. Still, it is something to look for if seeking a way out.

[John1122]

I don't think the GFS will pull the coup on this one, especially the cat 5 hanging around off the coast from Friday until Monday morning.  That may technically be possible but it seems a very unlikely scenario.

The 12z Euro features possible flooding rains for the far eastern mountains and a general soaking rain for the rest of us. The extreme NETN/SWVA rain event from the 00z Euro was pretty much cut in half on qpf totals. Still 4-6 inches of rain predicted in those areas, but much better than the 8-12 inches the 00z was showing.

[tnweathernut]

I'm actually concerned at the number of EPS members that head into SC then meander west and north........  Still a lot of uncertainty and I don't think the mountains can sleep on this one.  It would be nice to see more northwest movement sooner.  The longer it stays W or WNW the more trouble I think it can cause for areas inland toward the mountains.

[John1122]

The 00z Euro brings the remnants a little further west and south than 12z. Rain shield stretches towards Nashville now, with 1.5-4 inches from Cookeville and points east. The mountains sap it quite a bit, 8-12 inches of rain on the eastern slopes of the Apps. 3-5 at the peak and falling as you move westward with the storm weakening. The Euro also brings some 35-50mph wind gusts across the area. There's a peak gust in the 90s over the mountains of western NC right along the border east of Erwin.

The GFS was still wacky but this time took the remnants well back over the Eastern Valley areas and it ends up in a similar position as the Euro.

[Holston_River_Rambler]

8 minutes ago, *Flash* said:

Just catchin' up here. Interesting to see the continued theme of ridge magnitude being underestimated. Curious as to how far west/south trends will go. Lost 105.44-105.64 in week 1 of my fantasy football pro league, a fitting metaphor for my area with respect to the precip shield. Will take bonus cloud cover holding down temps on a busy outdoor weekend. On a separate note, anyone have a good resource where analogs can be accessed based on track? 

I found this site which does have an "experimental analogue track" section in a drop down menu for current storms or areas of potential development, but not sure if this is what you meant.

http://derecho.math.uwm.edu/models/  

[nrgjeff]

Latest NWP tracks show a pause and pivot in NC on Saturday; then, a start west on Sunday. The pivot is why I believe far northeast Tennessee (TRI) East KY, southwest VA, and of course NC should get a few to several inches of rain. Still the worst will stay east of here.

Meanwhile the CFS followed the Euro weeklies cooler (or at least less warm) later this month. Hopefully! This may be my last post of the week depending on Florence. Stay safe.

[John1122]

The Euro shift a little south/west again. Now has the heaviest rain in the Chattanooga area. Rain shield goes west of Nashville. Euro still has most areas from the Plateau and eastward getting tropical storm force gusts, some up to around 50mph outside the mountains. Some 50-70mph gusts in the mountains with hurricane force gusts at the highest peaks.

The rain lingers around from Sunday afternoon until finally clearing out on Wednesday on the Euro.

[Runman292]

A wild run with the 0z Euro to say the least....

[AMZ8990]

4 minutes ago, Carvers Gap said:

I think MRX's wording is excellent...

.LONG TERM (Thursday through Tuesday)... Hurricane Florence will
remain the focus of the long term forecast period. The mid/upper
level ridge will remain over our area for the latter part of the
work week.  Some mainly isolated convection will affect parts of the
area especially during the afternoon/evening hours, but most areas
will be precipitation free through Friday.  The track of Hurricane
Florence is still unclear at this point toward the end of the
period, but the official track brings what is left of it into our
vicinity by the latter part of the weekend and current models
suggest it`s remnants may bring significant rains to our area in the
Sunday through Tuesday time frame.  However, as steering currents
will be weak as Florence moves onshore and model solutions have been
erratic, there remains a high level of uncertainty as to the exact
track of this system once it comes ashore.  Will keep mention of
possible impacts from Florence in the HWO.

  I agree, carver.  Sure was a wild run from yesterday to this morning.  We all thought it was gonna come further south and it has.  I’ve got family in Charleston so I’m just hoping for the best for them right now.  This storm is something else though man.

[AMZ8990]

22 minutes ago, Carvers Gap said:

I highly doubt the track, once inland, is nailed down yet.  NE TN was on the left side of the cone two days ago.  Now, we are on the right.  I don't have a ton of confidence that this is going to go where it is currently modeled(once inland).  I do think it is going to meander - and that is not good for the communities in the SE US wherever that happens.  What we really need to hope for is that this storm picks up speed and does not stop.  I think the mountains of NC (southwest corner to northwest corner) need to really watch this.  Seems that one constant is that they are increasingly at risk of flooding rains of maybe an unusual scale.  It is still possible that Florence actually misses the southern Apps w a southern trend.  But again, w low steering currents this is going to have a mind of its own so to speak.  Interesting to follow but very concerned for coastal communities of the SE coast as this storm will slowly(and I mean slowly as modeled) move on shore after first making a SE jog(still not totally sure I buy that).  The Gulf Stream will fuel that storm in the northeast quadrant even if part of the storm is barely onshore.  Downsloping winds will be the story here.  That would likely mean that the eastern side of the eastern TN Valley would see less rain but decent downsloping winds.  Not sure what would happen when those winds hit the upslope of the Plateau, though I think I know what it should do which is rain.  Once the remnants of Florence move into Tennessee per the Euro, then NE TN gets rain.  Still, uncertainty is the key word.  Nothing set in stone, though like I said, the mountains of NC need to really watch this.   @Math/Met, would the 0z Euro create a tropical induced (sorry...don't know of a better term) mountain wave even in places like Camp Creek?  

Could the Bermuda high help any in giving this storm some push in the right direction.  Or are we past the point where the high could effect Florence now?

[stadiumwave]

Wish a single thread were made for Florence. Let's keep this thread for overall fall & winter pattern discussion if we could.

I know most are focused Florence right now & rightfully so. But holy moly on JMA Seasonal for DEC!! Average Oct, warm Nov. BUT DEC...robust -EPO, -NAO (blocking mostly around Davis Strait). Looks very similar to updated Euro:

The entire winter looks NUTS also. Look at 3 month first & you can change through individual OCT/NOV/DEC.

 

Then you can click on DEC-FEB mean on first page of link. Good stuff...if you like winter! Winter mean has robust -EPO, -NAO, -AO combo.

http://ds.data.jma.go.jp/tcc/tcc/products/model/map/4mE/map1/pztmap.php

[jaxjagman]

47 minutes ago, stadiumwave said:

Wish a single thread were made for Florence. Let's keep this thread for overall fall & winter pattern discussion if we could.

I know most are focused Florence right now & rightfully so. But holy moly on JMA Seasonal for DEC!! Average Oct, warm Nov. BUT DEC...robust -EPO, -NAO (blocking mostly around Davis Strait). Looks very similar to updated Euro:

The entire winter looks NUTS also. Look at 3 month first & you can change through individual OCT/NOV/DEC.

 

Then you can click on DEC-FEB mean on first page of link. Good stuff...if you like winter! Winter mean has robust -EPO, -NAO, -AO combo.

http://ds.data.jma.go.jp/tcc/tcc/products/model/map/4mE/map1/pztmap.php

Think i agree,either a thread should be made or move this to summer

[John1122]

We are in fall and it's part of the weather that's happening in the future. So I don't have any issue personally with it being here. But maybe we need a short term thread and we can leave this the long term thread for beyond 5 days discussion?